running.md

Running a data availability node

Prerequisites

1. PostgreSQL DB
2. Ethereum node (L1)
3. The Data Availability node (DAN) itself

Set up

These three components can run in many different ways. This guide provides instructions using the following setup:

• The L1 node is provided by a 3rd party, so you only need the L1 URL.
• The PostgreSQL instance, and the DAN, run in Docker containers configured using docker-compose.

Note: This is just one way to run the DAN. It's also possible to run the DAN using the binary and PostgreSQL in a managed instance via a cloud provider. There are also many more possible configurations.

Instructions

version: "3.5"
networks:
  default:
    name: cdk-data-availability

services:

  cdk-data-availability:
    container_name: cdk-data-availability
    restart: unless-stopped
    depends_on:
      cdk-data-availability-db:
        condition: service_healthy
    image: hermeznetwork/cdk-data-availability:v0.0.2
    deploy:
      resources:
        limits:
          memory: 1G
        reservations:
          memory: 512M
    ports:
      - 8444:8444
    volumes:
      - ./config.toml:/app/config.toml
      - ./private.keystore:/pk/test-member.keystore
    command:
      - "/bin/sh"
      - "-c"
      - "/app/cdk-data-availability run --cfg /app/config.toml"

  cdk-data-availability-db:
    container_name: cdk-data-availability-db
    restart: unless-stopped
    image: postgres:15
    healthcheck:
      test: ["CMD-SHELL", "pg_isready -d $${POSTGRES_DB} -U $${POSTGRES_USER}"]
      interval: 10s
      timeout: 5s
      retries: 5
    ports:
      - 5434:5432
    environment:
      - POSTGRES_USER=committee_user            # CHANGE THIS: use your preferred user name
      - POSTGRES_PASSWORD=committee_password    # CHANGE THIS: use a safe and strong password
      - POSTGRES_DB=committee_db
    command:
      - "postgres"
      - "-N"
      - "500"

1. Copy/paste the above into a new directory and name the file docker-compose.yml
2. In the same directory, create a file named config.toml and copy/paste the following:

PrivateKey = {Path = "/pk/test-member.keystore", Password = "testonly"} # CHANGE THIS (the password): according to the private key file password

[L1]
RpcURL = "http://URLofYourL1Node:8545"  # CHANGE THIS: use the URL of your L1 node, can be http(s) or ws(s)
PolygonValidiumAddress = "0x8dAF17A20c9DBA35f005b6324F493785D239719d"       # CHANGE THIS: Address of the Validium smart contract
DataCommitteeAddress = "0x68B1D87F95878fE05B998F19b66F4baba5De1aed"     # CHANGE THIS: Address of the data availability committee smart contract
Timeout = "3m"
RetryPeriod = "5s"
BlockBatchSize = 32
TrackSequencer = true
TrackSequencerPollInterval = "1m"

[Log]
Environment = "development" # "production" or "development"
Level = "debug"
Outputs = ["stderr"]

[DB]
User = "committee_user"             # CHANGE THIS: according to the POSTGRES_USER in docker-compose.yml
Password = "committee_password"     # CHANGE THIS: according to the POSTGRES_PASSWORD in docker-compose.yml
Name = "committee_db"
Host = "cdk-data-availability-db"
Port = "5432"
EnableLog = false
MaxConns = 200

[RPC]
Host = "0.0.0.0"
Port = 8444
ReadTimeout = "60s"
WriteTimeout = "60s"
MaxRequestsPerIPAndSecond = 500

3. Now you can generate a file for the Ethereum private key of the committee member. Note that this private key should be representing one of the addresses of the committee. To generate the private key, run:

docker run -d -v .:/key hermeznetwork/zkevm-node /app/zkevm-node encryptKey --pk **** --pw **** -o /key

Replace the **** for your actual private key and a password of your choice. After running the command, a file named UTC--... is generated. Rename it to private.keystore.

4. Change all the fields marked with CHANGE THIS on both the docker-compose.yml and config.toml.

5. Run it: docker compose up -d.

6. Check the logs to see if everything is going fine: docker compose logs.

Note: the DAN endpoint (in this example using the port 8444) should be reachable in the URL indicated on the data availability smart contract.